Spatial amplification of a laser wave and the transverse spread of electrons in an undulator with a noncollinear configuration

The spatial amplification of a wave in a magnetostatic undulator with noncollinear electron and laser beams is studied in the framework of the dispersion relation for single-frequency and collective regimes. The dependence of the gain on the electron beam width is estimated with regard to the spatial boundedness of the beams. The laser power threshold at which the selection with respect to the transverse velocity is possible is obtained for a free-electron laser without inversion.     

Magnetic fluid poly(ethylene glycol) with moderate anticancer activity

Poly(ethylene glycol) (PEG)-containing magnetic fluids - magnetite (Fe₃O₄) stabilized by sodium oleate - were prepared. Magnetic measurements confirmed superparamagnetic behaviour at room temperature. The structure of that kind of magnetic fluid was characterized using different techniques, including electron microscopy, photon cross correlation spectroscopy and small-angle neutron scattering, while the adsorption of PEG on magnetic particles was analyzed by differential scanning calorimetry and Fourier transform infrared spectroscopy. From the in vitro toxicity tests it was found that a magnetic fluid containing PEG (MFPEG) partially inhibited the growth of cancerous B16 cells at the highest tested dose (2.1 mg/ml of Fe₃O₄ in MFPEG).     

The influence of the molecular weight of DMC polyethers on the physical-mechanical properties of PU materials based on them

This article describes synthesis of polyurethane (PU) elastomers based on DMC polyethers. The influence of the molecular weight of DMC polyethers on the strength characteristics and mechanical hysteresis of model PU composites based on them is studied. It is shown that, when the molecular weight of DMC polyethers changes in the range of 2000–4000, the strength of PU materials dramatically increases, while a considerable improvement of elastic properties is observed when using polyethers with MW = 8.000 or higher.     

The effect of ply properties in paperboard converting operations: a way to increase formability

Cellulose - This study addresses the question of how the difference in mechanical properties of the individual layers in a multi-ply commercial paperboard affects the outcome of the tray-forming...     

Monocrystalline Quartz ICP Etching: Road to High-Temperature Dry Etching

Plasma Chemistry and Plasma Processing - In this study, the dry plasma-chemical etching process of monocrystalline SiO2 (quartz) in a fluoride-based (sulfur hexafluoride, SF6) inductively coupled...     

Observation of Spin and Valley Splitting of Landau Levels under Magnetic Tunneling in Graphene/Boron Nitride/Graphene Structures

Resonance magnetic tunneling in heterostructures formed by graphene single sheets separated by a hexagonal boron nitride barrier and bounded by two gates has been investigated in a strong magnetic field, which has allowed observing transitions between spin- and valley-split Landau levels with various indices belonging to different graphene sheets. An unexpected increase with the temperature in the interlayer tunneling conductance owing to transitions between the Landau levels in strong magnetic fields cannot be explained by existing theories.     

Scattering by randomly oriented thin ice disks with moderate equivalent-sphere size parameters

We use the T-matrix method to compute the scattering matrix for randomly oriented circular ice cylinders with diameter-to-length ratios 1 and 20 and surface-equivalent-sphere size parameters up to 12. We show that wavelength-sized, sharp-edged ice plates with extreme diameter-to-length ratios possess the same scattering properties as smooth platelike spheroids: their phase functions are similar to those of surface-equivalent compact particles, whereas all other elements of the scattering matrix are typical of Rayleigh scattering.     

Asynchronous parametric excitation: validation of theoretical results by electronic circuit simulation

Nonlinear Dynamics - A validation of recent theoretical results on the stability effects of asynchronous parametric excitation is presented. In particular, the coexistence of both resonance and...